Bullet holes and group shape tell the tale

[Klem]

I have been pondering that as well. Seems like that would violate the laws of physics to have a hole smaller than the bullet that passes through it. But, that guy is clearly the bench-rest expert.

I agree... it's probably Bench Rest jargon.

He might be saying that when the bullet is stable the hole is exactly the diameter of the bullet. But when not it is fractionally more oval as it yaws ever so slightly through the hole. Those clear plastic calibre checkers used by scoring officials in Prac Pistol might be one way of seeing the difference.

Or he might be referring to the total size of the group being one hole. Someone as good as he would be shooting single holes groups at close range. I have seen frames for a system of scrolling paper behind Bench Rest targets. While the front target looks like one hole they also count the separated holes in the moving paper to make sure the competitor did not fire a few at the target and then a couple deliberately off target. The scrolling paper stops cheats claiming they shot through the same hole.